Re: [PATCH] crypto: more robust crypto_memneq

[Cesar Eduardo Barros]

Em 25-11-2013 14:26, Daniel Borkmann escreveu:
> On 11/25/2013 04:59 PM, James Yonan wrote:
> > This approach using __asm__ ("" : "=r" (var) : "0" (var)) to try to
> > prevent compiler optimizations of var is interesting.
> >
> > I like the fact that it's finer-grained than -Os and doesn't preclude
> > inlining.
>
> Agreed. This looks much better than the Makefile workaround. Do we have
> a hard guarantee that in future, this will not be detected and optimized
> away by the compiler?

That guarantee is something only the compiler people can give you. But 
given that RELOC_HIDE will break if that ever changes, and there are 
other constructs depending on the optimization-blocking behavior of 
inline assembly (like the many kinds of barriers in the kernel), I am 
not worried about that.

--
Cesar Eduardo Barros
cesarb@xxxxxxxxxxxxx
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